Blame for README.md

# TouchEvent

## 1. Overview

The TouchEvent dataset belongs to Haptic Sensing Lab at the School of Advanced Manufacturing and Robotics, Peking University. TouchEvent contains synchronized time-series data from real-robot tactile experiments and finite element method (FEM/IPC) simulations. It covers objects with different shapes, materials, and sizes and is organized into four task families:

- `Fixed`: pressing, lifting, and slipping at a fixed contact position;
- `Free`: picking and insertion at different gripper widths;
- `Obstacle_avoidance`: obstacle-avoidance experiments at different contact positions and depths;
- `Integrated_tasks`: multi-stage experiments involving a paired ball and cylinder.

Depending on the task, the data include robot end-effector poses, gripper states, force/torque or tactile-channel measurements, simulated motion, FEM node displacements, and nodal contact forces. Vision-based tactile branches also provide camera images associated with the CSV records.

Dataset page: <https://huggingface.co/datasets/BAAI/TouchEvent>

## 2. Top-Level Structure

```text
TouchEvent/
├── Fixed/
│   ├── digit/
│   ├── s1/
│   └── s2/
├── Free/
│   ├── digit/                 # Repository name; this branch represents DIGIT
│   ├── s1/
│   └── s2/
├── Integrated_tasks/
└── Obstacle_avoidance/
```

Sensor identifiers:

| Identifier | Description |
|---|---|
| `digit` | DIGIT vision-based tactile sensor |
| `s1` | Spherical vision-based tactile sensor |
| `s2` | Ellipsoidal vision-based tactile sensor |
| `s3` | Large-area resistive tactile sensor with 12 raw channels |


## 3. Object Naming

Object directories follow this convention:

```text
<shape>_<material>_<size>
```

Examples:

```text
ball_0010_10
cylinder_PLA_17.5
```

### 3.1 Shapes

- `ball`: spherical contact object;
- `cylinder`: cylindrical contact object.

### 3.2 Materials

| Code | Material |
|---|---|
| `0010` | Ecoflex 00-10 |
| `0030` | Ecoflex 00-30 |
| `0050` | Ecoflex 00-50 |
| `15A` | Dragon Skin 15 |
| `PLA` | PLA |

### 3.3 Sizes

The size codes are `10`, `12.5`, `15`, `17.5`, and `20`. They represent the nominal object radius in millimeters.

A complete single-object branch in `Fixed`, `Free`, or `Obstacle_avoidance` contains `2 × 5 × 5 = 50` shape-material-size combinations. `Integrated_tasks` instead uses selected pairs of complete object identifiers. Because the repository may continue to receive updates, check the relevant online directory for the combinations currently available.

## 4. `Fixed`: Fixed-Position Contact

### 4.1 Directory Structure

```text
Fixed/
└── <sensor>/
    └── <shape>_<material>_<size>/
        ├── press_depth_01/
        │   ├── up/
        │   │   ├── camera_frames_60hz.tar
        │   │   ├── fem_node.csv
        │   │   ├── franka_data.csv
        │   │   ├── multimodal_aligned_data.csv
        │   │   ├── real_sim_motion_alignment.csv
        │   │   └── simulation_data.csv
        │   └── down/
        │       └── ...
        ├── press_depth_02/
        └── ...
```

Each object condition contains up to ten press-depth settings, from `press_depth_01` to `press_depth_10`. Every depth is divided into two motion stages:

- `up`: lifting or upward motion;
- `down`: pressing, downward motion, or slipping.

The current `Fixed` data are aligned in the displacement domain. Sixty positions are selected for each stage and reindexed from `0` to `59`. The files `simulation_data.csv`, `real_sim_motion_alignment.csv`, `franka_data.csv`, and `multimodal_aligned_data.csv` contain one row per aligned frame. `fem_node.csv` contains multiple node records per frame, so it should have 60 unique frames rather than 60 rows.

### 4.2 File Descriptions

#### `franka_data.csv`

Real-robot task and control-cycle data, including:

- ROS, robot, and sensor timestamps;
- task state and cycle index;
- commanded and measured gripper widths;
- actual and commanded Franka end-effector positions and quaternion orientations;
- processed, raw, and online-baseline XJC force/torque measurements;
- Franka-estimated six-axis end-effector force/torque;
- directional forces, force reference, detachment detection, and commanded Z-axis velocity and acceleration.

#### `multimodal_aligned_data.csv`

The main camera-centered, real-world multimodal alignment table, including:

- camera sequence number, nanosecond timestamp, image path, and resolution;
- timestamp correspondences among the task, robot, XJC force sensor, and gripper;
- actual and commanded end-effector poses;
- XJC and Franka six-axis force/torque values;
- position, velocity, measured effort, and external torque for the seven arm joints;
- position, velocity, effort, and total width for the two gripper fingers.

#### `simulation_data.csv`

Frame-level simulated force/torque curves with the following fields:

```text
frame, time_s, phase, command_travel_m,
Fx_N, Fy_N, Fz_N, Mx_Nm, My_Nm, Mz_Nm,
delta_Fx_N, delta_Fy_N, delta_Fz_N,
delta_Mx_Nm, delta_My_Nm, delta_Mz_Nm,
delta_force_norm_N, delta_moment_norm_Nm
```

#### `real_sim_motion_alignment.csv`

A real-to-simulation motion mapping table containing:

- `frame`, `time_s`, `phase`, and `camera_time_ns`;
- relative displacement and absolute coordinates of the real end effector;
- relative displacement and absolute coordinates of the Isaac TCP;
- relative displacement and absolute coordinates of the IPC contact-region midpoint.

#### `fem_node.csv`

Surface-node data from the FEM simulation:

| Field | Description | Unit |
|---|---|---|
| `frame` / `aligned_frame` | Frame index | — |
| `time_s` / `aligned_time_s` | Simulation or aligned time | s |
| `node_id` | Node identifier | — |
| `x_m`, `y_m`, `z_m` | Node coordinates | m |
| `ux_m`, `uy_m`, `uz_m` | Node displacements | m |
| `fx_N`, `fy_N`, `fz_N` | Nodal contact forces | N |

#### `camera_frames_60hz.tar`

An archive containing the image directory referenced by `camera_image_path` in the CSV files. Extract it with:

```bash
tar -xf camera_frames_60hz.tar
```

The `60hz` suffix is retained from the aligned export naming convention. For time synchronization, use the frame indices and nanosecond timestamps stored in the CSV files.

## 5. `Free`: Free Picking and Insertion

### 5.1 Directory Structure

```text
Free/
└── <sensor>/
    └── <shape>_<material>_<size>/
        ├── width_01/
        │   ├── insert/
        │   │   ├── camera_frames_60hz.tar
        │   │   ├── fem_node.csv
        │   │   ├── franka_data.csv
        │   │   └── simulation_data.csv
        │   └── pick/
        │       └── ...
        ├── width_02/
        └── ...
```

Each object condition contains ten gripper-width settings, from `width_01` to `width_10`. The measured width is recorded in `franka_data.csv` as `measured_gripper_width_m`; do not infer a physical width solely from the directory index.

- `pick`: lifting or picking the object;
- `insert`: lateral motion, insertion, holding, return, and final insertion.

`Free` sequences have variable lengths and should not be assumed to contain 60 frames. The three CSV files are aligned through `aligned_frame`, `aligned_time_s`, and their phase fields.

### 5.2 File Descriptions

#### `franka_data.csv`

An aligned real-robot table with 13 fields:

```text
aligned_frame, aligned_time_s, alignment_phase, task_ros_time_ns,
camera_image_path,
robot_ee_x_m, robot_ee_y_m, robot_ee_z_m,
robot_ee_qx, robot_ee_qy, robot_ee_qz, robot_ee_qw,
measured_gripper_width_m
```

#### `simulation_data.csv`

An aligned simulation-motion table with seven fields:

```text
aligned_frame, aligned_time_s, alignment_phase,
gripper_y_m, gripper_z_m,
ipc_midpoint_y_m, ipc_midpoint_z_m
```

#### `fem_node.csv`

Aligned node-level FEM data. In addition to the node coordinates, displacements, and contact forces described in Section 4.2, this file contains a `phase` column.

#### Legacy `.bak` File in the DIGIT Branch

Some action directories under `Free/digit` also contain:

```text
camera_franka_gripper_aligned_60hz.csv.bak
```

This is a retained legacy or backup alignment table. Use the standardized `franka_data.csv` for normal analysis. Read the `.bak` file only when additional legacy columns are needed for traceability.

## 6. `Obstacle_avoidance`: Obstacle Avoidance

### 6.1 Directory Structure

```text
Obstacle_avoidance/
└── <shape>_<material>_<size>/
    ├── position_01/
    │   ├── depth_01/
    │   │   ├── fem_node.csv
    │   │   ├── franka_data.csv
    │   │   └── simulation_data.csv
    │   ├── depth_02/
    │   └── ...
    ├── position_02/
    └── ...
```

Each object condition contains 12 contact positions, from `position_01` to `position_12`. Every position contains five depths, from `depth_01` to `depth_05`. These directory names are discrete experimental-condition identifiers. Use the end-effector pose, Isaac/IPC coordinates, and phase fields in the CSV files for the physical trajectory.

### 6.2 File Descriptions

#### `franka_data.csv`

Real-world obstacle-avoidance data with 23 fields:

```text
aligned_frame, aligned_time_s, alignment_phase,
channel_01_raw, ..., channel_12_raw,
ee_x_m, ee_y_m, ee_z_m,
ee_qx, ee_qy, ee_qz, ee_qw,
unix_time_ns
```

`channel_01_raw` through `channel_12_raw` are the 12 raw tactile channels. The `ee_*` fields describe the Franka end-effector pose.

#### `simulation_data.csv`

A simulated motion trajectory with nine fields:

```text
frame, time_s, phase,
isaac_x_m, isaac_y_m, isaac_z_m,
ipc_x_m, ipc_y_m, ipc_z_m
```

#### `fem_node.csv`

Frame- and node-level coordinates, displacements, and three-axis contact forces. Its fields follow the common `fem_node.csv` definition in Section 4.2.

## 7. `Integrated_tasks`: Integrated Multi-Stage Tasks

### 7.1 Directory Structure

```text
Integrated_tasks/
└── <ball_object>_<cylinder_object>/
    ├── pose1/
    │   ├── width1/
    │   │   ├── camera_frames_60hz.tar
    │   │   ├── fem_data.csv
    │   │   ├── fem_node.csv
    │   │   └── franka_s3_data.csv
    │   ├── width2/
    │   └── ...
    ├── pose2/
    └── ...
```

Unlike the single-object directory names used by the other task families, an integrated-task directory concatenates two complete object identifiers. The first identifier describes the ball and the second describes the cylinder. Examples currently present in the repository include:

```text
ball_0010_20_cylinder_0010_20
ball_0010_20_cylinder_0030_20
ball_0010_20_cylinder_0050_17.5
ball_0010_20_cylinder_15A_20
```

Each paired-object condition may contain up to five pose settings, `pose1` through `pose5`, and each pose may contain up to eight width settings, `width1` through `width8`. These are ordinal experimental-condition identifiers; note that they do not use the zero-padded naming convention found in `Free`.

The integrated sequence combines gripper closing, lifting/probing, retreating, a smooth multi-pose motion, and gripper opening. Real-world phase labels include `CLOSE_GRIPPER`, `POSE1_TO_POSE2`, `POSE2_TO_POSE3`, `POSE3_TO_POSE4`, `SMOOTH_POSE4_TO_POSE8`, and `OPEN_AT_POSE8`. Simulation phases provide more detailed sub-stages such as calibrated delays, stable periods, and fault guards.

Integrated-task sequences have variable lengths and should not be assumed to contain 60 frames. Align their files using `frame` and `time_s`.

### 7.2 File Descriptions

#### `franka_s3_data.csv`

A 24-field real-world table combining Franka motion, camera references, and S3 tactile readings:

```text
frame, time_s, camera_ros_time_ns, phase, image_relative_path,
ee_x_m, ee_y_m, ee_z_m,
ee_qx, ee_qy, ee_qz, ee_qw,
arduino_ch00_raw, ..., arduino_ch11_raw
```

The `ee_*` fields describe the Franka end-effector pose. The twelve `arduino_ch*_raw` fields are raw tactile channels from the S3 sensor. `image_relative_path` identifies the corresponding frame in `camera_frames_60hz.tar`.

#### `fem_data.csv`

A nine-field simulation-motion table:

```text
frame, time_s, phase,
isaac_x_m, isaac_y_m, isaac_z_m,
ipc_midpoint_x_m, ipc_midpoint_y_m, ipc_midpoint_z_m
```

It records the Isaac reference position and IPC contact-region midpoint for every simulation frame.

#### `fem_node.csv`

The integrated-task node table uses a **wide format**, unlike the long node format used by `Fixed`, `Free`, and `Obstacle_avoidance`. Each row represents one frame and starts with:

```text
frame, time_s, alignment_displacement_progress
```

The remaining columns are grouped by node identifier. Every selected node contributes nine values:

```text
node_<id>_x_m,  node_<id>_y_m,  node_<id>_z_m,
node_<id>_ux_m, node_<id>_uy_m, node_<id>_uz_m,
node_<id>_fx_N, node_<id>_fy_N, node_<id>_fz_N
```

Current files contain 2,010 columns: three frame-level fields followed by nine fields for each of 223 selected nodes. Node identifiers are encoded in the column names and are not necessarily contiguous.

#### `camera_frames_60hz.tar`

The camera archive contains the frames referenced by `image_relative_path` in `franka_s3_data.csv`. Extract it in the corresponding width directory before resolving image paths.

## 8. Alignment and Unit Conventions

- `frame` and `aligned_frame` start at 0;
- fields ending in `*_time_s` are expressed in seconds;
- fields ending in `*_time_ns` are expressed in nanoseconds;
- position and displacement fields ending in `_m` are expressed in meters;
- force fields ending in `_N` are expressed in newtons;
- moment fields ending in `_Nm` are expressed in newton-meters;
- quaternions follow the `qx, qy, qz, qw` order;
- align tables within a sequence by frame index first, then use timestamps for validation;
- in the long-format `fem_node.csv` files used by `Fixed`, `Free`, and `Obstacle_avoidance`, use the frame index together with `node_id` as the node-record key;
- in the wide-format `Integrated_tasks/fem_node.csv`, each row is one frame and node identifiers are embedded in column names.